PROJECT SUMMARY/ABSTRACT Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the United States. Strong evidence indicates that statin medications can reduce the risk of CVD. For patients with existing CVD, statins have been shown to reduce mortality. Despite this evidence, statins are under-prescribed and this contributes to disparities in cardiovascular care that exist based on sociodemographic factors such as race/ethnicity, income, and insurance. The growing adoption of the electronic health record (EHR) brings new opportunities to improve clinician decision- making toward higher-value care. Behavioral economists have used insights from psychology and human behavior to modify choice architecture to influence decision-making without restricting choice. These approaches, often termed as ?nudges, include changing defaults options to make the optimal choice the easy one, using active choice framing to prompt decision-making to occur now rather than be pushed off into the future, and strategically framing information such as social comparison feedback to use social influences and norms to encourage behavior change. While these approaches are commonly used throughout other industries, systematic adoption and validation within health care settings has been limited. In 2016, our group formed the Penn Medicine Nudge Unit, a first-of-its-kind initiative within a health care setting that brings together a multidisciplinary team focused on designing, testing, and scaling the use of nudges within the EHR to improve health care delivery at the University of Pennsylvania Health System. In this study, we will test the feasibility and effectiveness of using nudges within the EHR to increase the rate at which statin medications are prescribed to patients for whom national practice guidelines indicate should be on statins. We will demonstrate the feasibility of integrating an active choice intervention in the electronic health record that prompts physicians to review and make decisions on a list of their patients eligible for statin therapy. We will then conduct a one- year, pragmatic three-arm cluster randomized trial to compare the effect of the active choice intervention with and without monthly social comparisons feedback to a control group. We will evaluate if the interventions reduce disparities in care based on sociodemographic characteristics and its impact on LDL levels.